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This thesis provides an in-depth investigation of effective non-Hermiticity and topology in many-mode, non-interacting, bosonic systems. It also establishes the extent to which one must move beyond the Hamiltonian, closed-system setting, in order to uncover signatures of genuine symmetry-protected topological (SPT) physics in'free'(mean-field) bosons. While SPT phases of free fermionic matter and their associated zero-energy boundary-localized modes have been thoroughly explored, similar physics in free bosonic systems still remains elusive. No fermionic counterpart exists for the distinctive dynamical behavior that arises from the effective non-Hermiticity, intrinsic even at equilibrium, to bosonic Hamiltonians. Therefore, a much needed paradigm shift is required to address major conceptual roadblocks in the search for SPT bosonic phases.The analysis within develops, in particular, the notion of topological metastability in quadratic bosonic systems subject to Markovian dissipation. The resulting dynamical paradigm was found to be characterized by both a sharp separation between transient and asymptotic dynamics and non-trivial topological invariants. It also features long-lived boundary-localized'Majorana boson'and'Dirac boson'modes, which realize tight bosonic analogues to the edge modes characteristic of fermionic SPT phases. This comprehensive look into non-interacting bosonic systems breaks important new ground for re-imagining quantum phenomena beyond equilibrium, with novel applications in quantum science.

Confinement and manipulation of photons using microcavities have triggered intense research interest in both basic and applied physics for more than a decade. Prominent examples are whispering gallery microcavities which confine photons by means of continuous total internal reflection along a curved and smooth surface. The long photon lifetime, strong field confinement, and in-plane emission characteristics make them promising candidates for enhancing light-matter interactions on a chip. In this book, we will introduce different ultra-high-Q whispering gallery microcavities, and focus on their applications in enhancing light-matter interaction, such as ultralow-threshold microlasing, highly sensitive optical biosensing, nonlinear optics, cavity quantum electrodynamics and cavity optomechanics.

This thesis presents several important aspects of the plasma dynamics in extremely high intensity electromagnetic fields when quantum electrodynamics effects have to be taken into account. This work is of utmost importance for the forthcoming generation of multipetawatt laser facilities where this physics will be tested. The first part consists of an introduction that extends from classical and quantum electrodynamics in strong fields to the kinetic description of plasmas in the interaction with such fields. This can be considered as an advanced tutorial which would be extremely useful to researchers and students new to the field. The second part describes original contributions on the analysis of the signatures of classical and quantum radiation reaction on the distribution function of the charged particles and of the photon spectrum, and leads to significant advances on this topic. These results are then extended to the analysis of the so-called QED cascades which are ofcentral importance for a better understanding of some astrophysical phenomena and basic physics problems. Finally, the book discusses future directions for the high intensity laser–plasma interaction community. The results presented in this thesis are expected to become more and more relevant as the new multipetawatt facilities become operative.

Light and Vacuum presents a synthesis of selected fundamental topics of electromagnetic wave theory and quantum electrodynamics (QED) and analyzes the main theoretical difficulties encountered to ensure a coherent mathematical description of the simultaneous wave-particle nature of light, put in evidence by the experiments. The notion and the role of the quantum vacuum, strongly related to light, are extensively investigated.Classical electrodynamics issued from Maxwell's equations revealed the necessity of introducing the notion of volume for an electromagnetic wave to stand entailing precise values of cut-off wavelengths to account for the shape and dimensions of the surrounding space. Conversely, in QED, light is considered to be composed of point particles disregarding the conceptual question on how the frequency of oscillating electric and magnetic fields may be attributed to a point particle.To conciliate these concepts, the book provides a comprehensive overview of the author's work, including innovative contributions on the quantization of the vector potential amplitude at a single photon state, the non-local simultaneous wave-particle mathematical representation of the photon and finally the quantum vacuum. The purpose of the advanced elaborations is to raise questions, give hints and answers, and finally aspire for further theoretical and experimental studies in order to improve our knowledge and understanding on the real essence of Light and Vacuum.In this new edition, improvements have been made to the various chapters taking into account the actual status of the knowledge in this field. The photon wave function is further analyzed and a new concept of quantum vacuum is advanced compatible with recent astrophysical observations.

In this thesis, ultimate sensitive measurement for weak force imposed on a suspended mirror is performed with the help of a laser and an optical cavity for the development of gravitational-wave detectors. According to the Heisenberg uncertainty principle, such measurements are subject to a fundamental noise called quantum noise, which arises from the quantum nature of a probe (light) and a measured object (mirror). One of the sources of quantum noise is the quantum back-action, which arises from the vacuum fluctuation of the light. It sways the mirror via the momentum transferred to the mirror upon its reflection for the measurement. The author discusses a fundamental trade-off between sensitivity and stability in the macroscopic system, and suggests using a triangular cavity that can avoid this trade-off. The development of an optical triangular cavity is described and its characterization of the optomechanical effect in the triangular cavity is demonstrated. As a result, for the first time in the world the quantum back-action imposed on the 5-mg suspended mirror is significantly evaluated. This work contributes to overcoming the standard quantum limit in the future.

The physics of strong light-matter coupling has been addressed in different scientific communities over the last three decades. Since the early eighties, atoms coupled to optical and microwave cavities have led to pioneering demonstrations of cavity quantum electrodynamics, Gedanken experiments, and building blocks for quantum information processing, for which the Nobel Prize in Physics was awarded in 2012. In the framework of semiconducting devices, strong coupling has allowed investigations into the physics of Bose gases in solid-state environments, and the latter holds promise for exploiting light-matter interaction at the single-photon level in scalable architectures. More recently, impressive developments in the so-called superconducting circuit QED have opened another fundamental playground to revisit cavity quantum electrodynamics for practical and fundamental purposes.This book aims at developing the necessary interface between these communities, by providing future researchers with a robust conceptual, theoretical and experimental basis on strong light-matter coupling, both in the classical and in the quantum regimes. In addition, the emphasis is on new forefront research topics currently developed around the physics of strong light-matter interaction in the atomic and solid-state scenarios.

Light and Vacuum presents a synthesis of selected fundamental topics of electromagnetic wave theory and quantum electrodynamics (QED) and analyzes the main theoretical difficulties encountered to ensure a coherent mathematical description of the simultaneous wave-particle nature of light, put in evidence by the experiments. The notion and the role of the quantum vacuum, strongly related to light, are extensively investigated.Classical electrodynamics issued from Maxwell's equations revealed the necessity of introducing the notion of volume for an electromagnetic wave to stand entailing precise values of cut-off wavelengths to account for the shape and dimensions of the surrounding space. Conversely, in QED, light is considered to be composed of point particles disregarding the conceptual question on how the frequency of oscillating electric and magnetic fields may be attributed to a point particle.To conciliate these concepts, the book provides a comprehensive overview of the author's work, including innovative contributions on the quantization of the vector potential amplitude at a single photon state, the non-local simultaneous wave-particle mathematical representation of the photon and finally the quantum vacuum. The purpose of the advanced elaborations is to raise questions, give hints and answers, and finally aspire for further theoretical and experimental studies in order to improve our knowledge and understanding on the real essence of Light and Vacuum.

In the last few years it was seen the emergence of various new quantum phenomena specifically related with electronic or optical confinement on a sub-wavelength-size. Fast developments simultaneously occurred in the field of Atomic Physics, notably through various regimes of Cavity Quantum Electrodynamics, and in Solid State Physics, with advances in Quantum Well technology and Nanooptoelectronics. Simultaneously, breakthroughs in Near-Field­ Optics provided new tools which should be widely applicable to these domains. However, the key concepts used to describe these new and partly related effects are often very different and specific of the Community involved in a given development. It has been the ambition of the Meeting held at'Centre de Physique des Houches'to give an opportunity to specialists of different Communities to deepen their understanding of advances more or less intimately related to their own field, while presenting the basic concepts of these different fields through pedagogical Introductions. The audience comprised advanced students, postdocs and senior scientists, with a balanced participation of Atomic Physicists and Solid State Physicists, and had a truly international character. The considerable efforts of the lecturers, in order to present exciting new results in a language accessible to the whole audience, were the essential ingredients to achieve successfully what was the main goal of this School.

The control of optical modes in microcavities or in photonic bandgap (PBG) materials is coming of age! Although these ideas could have been developed some time ago, it is only recently that they have emerged, due to advances in both atomic physics and in fabrication techniques, be it on the high-quality dielectric mirrors required for high-finesse Fabry­ Perot resonators or in semiconductor multilayer deposition methods. Initially the principles of quantum electro-dynamics (QED) were demonstrated in elegant atomic physics experiments. Now solid-state implementations are being investigated, with several subtle differences from the atomic case such as those due to their continuum of electronic states or the near Boson nature of their elementary excitations, the exciton. Research into quantum optics brings us ever newer concepts with potential to improve system performance such as photon squeezing, quantum cryptography, reversible taps, photonic de Broglie waves and quantum computers. The possibility of implementing these ideas with solid-state systems gives us hope that some could indeed find their way to the market, demonstrating the continuing importance of basic research for applications, be it in a somewhat more focused way than in earlier times for funding.

'Quantum Theory of Near-field Electrodynamics'gives a self-contained account of the fundamental theory of field-matter interaction on a subwavelength scale. The quantum physical behavior of matter (atoms and mesoscopic media) in both classical and quantum fields is treated. The role of local-field effects and nonlocal electrodynamics, and the tight links to the theory of spatial photon localization are emphasized. The book may serve as a reference work in the field, and is of general interest for physicists working in quantum optics, mesoscopic electrodynamics and physical optics. The macroscopic and microscopic classical theories form a good starting point for the quantum approach, and these theories are presented in a manner appropriate for graduate students entering near-field optics.

Authored by one of the founders and major players in this field of research, this is a thorough and comprehensive approach to the quantum mechanical output coupling theory of lasers -- an important area of optical physics that has so far been neglected in the scientific literature. Clearly structured, the various sections cover one-dimensional optical cavity, laser, and microcavity laser with output coupling, atom-field interaction in a free-dimensional space, 3D analysis of spontaneous emission in a planar microcavity with output coupling, plus two-atom spontaneous emission. With numerous end-of-chapter problems, this is vital reading for theoretical physicists, laser specialists, and physicists in industry, as well as students and lecturers in physics.

The measurements of the Hall coe?cient R and the Seebeck coe?cient H (thermopower) S are known to give the sign of the carrier charge q. Sodium (Na) forms a body-centered cubic (BCC) lattice, where both R and S are H negative, indicating that the carrier is the “electron. ” Silver (Ag) forms a face-centered cubic (FCC) lattice, where the Hall coe?cient R is negative H but the Seebeck coe?cient S is positive. This complication arises from the Fermi surface of the metal. The “electrons” and the “holes” play important roles in conducting matter physics. The “electron” (“hole”), which by de?- tion circulates counterclockwise (clockwise) around the magnetic?eld (?ux) vector B cannot be discussed based on the prevailing equation of motion in the electron dynamics: dk/dt = q(E +v×B), where k = k-vector, E = electric?eld, and v = velocity. The energy-momentum relation is not incorporated in this equation. In this book we shall derive Newtonian equations of motion with a s- metric mass tensor. We diagonalize this tensor by introducing the principal masses and the principal axes of the inverse-mass tensor associated with the Fermi surface. Using these equations, we demonstrate that the “electrons” (“holes”) are generated, depending on the curvature sign of the Fermi s- face. The complicated Fermi surface of Ag can generate “electrons” and “holes,” and it is responsible for the observed negative Hall coe?cient R H and positive Seebeck coe?cient S.

Optical microcavities are structures that enable confinement of light to microscale volumes. The universal importance of these structures has made them indispensable to a wide range of fields. This important book describes the many applications and the related physics, providing both a review and a tutorial of key subjects by leading researchers from each field. The topics include cavity QED and quantum information, nanophotonics and nanostructure interactions, wavelength switching and modulation in optical communications, optical chaos and biosensors.

Recent advances in semiconductor technology have made it possible to fabricate microcavity structures in which both photon fields and electron-hole pairs (or excitons) are confined in a small volume comparable to their wavelength. The radiative properties of the electron-hole pairs and excitons are modified owing to the drastic change in the structure of the electromagnetic-field modes. This book is the first to give a comprehensive account of the theory of semiconductor cavity quantum electrodynamics for such systems in the weak-coupling and strong-coupling regimes. The important concepts are presented, together with relevant, recent experimental results.

L'objectif : donner au lecteur des bases solides sur la description quantique du champ électromagnétique, pour aborder efficacement l'étude des processus d'interaction entre atomes et photons tels qu'ils apparaissent en physique atomique et moléculaire, en optique quantique et en physique des lasers.

The dielectric microstructures act as ultrahigh Q factors optical cavities, which modify the spontaneous emission rates and alter the spatial distributions of the input and output radiation. The editors have selected leading scientists who have made seminal contributions in different aspects of optical processes in microcavities. Every attempt has been made to unify the underlying physics pertaining to microcavities of various shapes. This book begins with a chapter on the role of microcavity modes with additional chapters on how these microcavity modes affect the spontaneous and stimulated emission rates, enhance nonlinear optical processes, used in cavity-QED and chemical physics experiments, aid in single-molecule detection, influence the design of microdisk semiconductor lasers, and how deformed cavities can be treated with classical chaos theory.